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32-bit Applications on 64-bit Windows
As you probably know, the processor, operating system and applications on a PC may be 32-bit or 64-bit. CPU-s we have in our computers are 64-bit for a long time already. Windows XP tended to be used in 32-bit version, but now I can see most people use Windows 7/8/8.1/10 in 64-bit version as well. Only apps still exist in various forms. Shell extensions and drivers must match the version of the operating system, but other programs can be used in 32-bit version even on 64-bit system. Different combinations are possible:
We may ask a question about where does Windows store files and settings of such apps. It is especially interesting as the answer is very counter-intuitive. Location for (2) – 64-bit apps on 64-bit Windows – may contain “32” in its name (because of backward compatibility), while location for (3) – 32-bit apps on 64-bit Windows – may contain “64” (because of the name WoW64). Here is the list of such locations:
Program Files folder:
(Same applies to HKEY_CURRENT_USER.)